Mexican Drug Cartel Leaves Sack of Severed Human Heads Near Elementary School

Five severed human heads were found outside a Mexican elementary school Tuesday in the latest escalation in gruesome drug cartel violence.

State police said the heads, which appear to be male, were found in a sack along with a handwritten message threatening three alleged drug traffickers. Headless bodies found elsewhere in the city a day earlier were too badly burned to immediately determine their gender and make a possible match.

Watch Reuters' report on the recent violence:

It's unclear whether the grisly discovery is related to extortion threats that led about 140 elementary schools in the city to temporarily close earlier this month after teachers and parents decided it wasn't safe enough to start classes.

Last week, 35 bodies were found in Veracruz, Mexico. Over the weekend, a journalist was found decapitated after she used social media to cover cartel violence.

The Daily Mail reports that the note contained threats toward three alleged drug traffickers and Guerro State Governor Angel Aguierre:

The message, in an apparently sarcastic tone, told people to thank the governor for continuing 'this war'.

Earlier this week, the Mexican government reported it was investigating two videos posted on the Internet of masked men who were stating were taking action against the violent Zetas drug cartel themselves, but the government opposes this vigilante method.

In the most recent video, posted over the weekend, the group says it is attacking the Zetas because people are tired of the gang's kidnappings and extortion.

"We are the armed wing of the people, and for the people," says a man with a ski mask, who is seen in the video sitting at a table with four other masked associates and reading from a prepared statement. "We are anonymous warriors, with faces, but proudly Mexican." The speaker said his group was prohibited by its ethical code from carrying out kidnappings or extortion.

No group has formally claimed responsibility for that video, but the language and style of the declaration were similar to a video released in July, in which about two dozen armed men claimed to be "Mata Zetas" from the Jalisco Nueva Generacion cartel, or New Generation cartel, a group linked to the Sinaloa cartel.

The Interior Department said in a statement Monday night that the Attorney General's office "has opened an investigation into the videos that express the aforementioned ideas and are circulating on the Internet."

"While it is true that the criminal organization known as the Zetas should be defeated, that must occur by legal means and never by methods outside the law," the statement said.

While Mexican video-sharing sites and blogs frequently feature alleged statements by cartels, the "Mata Zetas" videos are being taken more seriously after a gang dumped 35 bound, seminude, tortured bodies on a busy avenue in front of horrified motorists in the Gulf coast city of Veracruz.

All 35 victims were linked to the Zetas cartel, and the killers were believed to be from the New Generation gang, said an official of the Mexican armed forces who couldn't be quoted by name for security reasons.

In addition, over the weekend, a newspaper editor was decapitated for what Amnesty International said Monday was for her speaking out against the drug cartels on social media networks. According to CNN, this is the fourth journalist to be killed this year in Mexico.

The Associated Press contributed to this report.